Treatment of Hypoaldosteronism
The primary treatment for hypoaldosteronism is fludrocortisone 50-200 μg once daily taken in the morning, combined with liberal salt intake. 1, 2, 3
Core Treatment Approach
Mineralocorticoid Replacement
- Fludrocortisone is the cornerstone of therapy, typically started at 50-100 μg daily and titrated up to 200 μg based on clinical response 1, 2
- The medication should be taken as a single morning dose 1
- Higher doses (up to 500 μg daily) may be required in children, younger adults, or during the third trimester of pregnancy when progesterone counteracts mineralocorticoid effects 1
- FDA approval specifically includes fludrocortisone for primary and secondary adrenocortical insufficiency 3
Dietary Sodium Management
- Unrestricted salt intake and consumption of salty foods should be encouraged 1, 2
- Patients should avoid potassium-containing salt substitutes 2
- Dietary potassium restriction is recommended as a general measure 4
Monitoring Parameters
Clinical Assessment
- Monitor blood pressure in both supine and standing positions to detect orthostatic hypotension 1, 2
- Assess for salt cravings or lightheadedness, which indicate under-replacement 1, 2
- Check for peripheral edema, which suggests over-replacement 1
- Monitor body weight 2
Laboratory Monitoring
- Serum electrolytes (sodium and potassium) require regular monitoring 2, 4
- Plasma renin activity is not reliable during pregnancy due to physiologic increases 1
Special Clinical Situations
Pregnancy Considerations
- Fludrocortisone dose often needs to be increased during late pregnancy due to progesterone's anti-mineralocorticoid effects 1, 2
- Salt cravings, blood pressure, and serum electrolytes become the primary monitoring parameters since plasma renin activity is unreliable 1
Concurrent Hypertension
- If essential hypertension develops in a patient with primary adrenal insufficiency, reduce the fludrocortisone dose but do not discontinue it 1, 2
- Add a vasodilator rather than stopping mineralocorticoid replacement 1
Critical Drug Interactions and Contraindications
Medications to Avoid
- Diuretics should be avoided as they counteract fludrocortisone effects 1, 2
- Acetazolamide must be avoided 1, 2
- NSAIDs should be avoided 1, 2
- Carbenoxolone and licorice potentiate mineralocorticoid effects and should be avoided 1, 2
- Grapefruit juice potentiates mineralocorticoid effects and should be avoided 1, 2
Medications Requiring Dose Adjustment
Common Pitfalls
Under-Replacement Recognition
- Under-replacement is common and often compensated for by over-replacement of glucocorticoids 1
- This pattern may predispose patients to recurrent adrenal crises 1
- Persistent salt cravings, orthostatic symptoms, or hyperkalemia suggest inadequate dosing 1, 2
Distinguishing Hypoaldosteronism Types
- Hyporeninemic hypoaldosteronism (most common in adults over 50 years with diabetes or nephropathy) typically responds to low-dose fludrocortisone 4
- Primary adrenal insufficiency requires both glucocorticoid (hydrocortisone 15-25 mg daily in divided doses) and mineralocorticoid replacement 1, 2
- Pseudohypoaldosteronism type I (aldosterone resistance) requires potassium restriction, sodium bicarbonate, and loop diuretics rather than fludrocortisone 5
Diagnostic Confusion
- High aldosterone levels in early infancy do not rule out aldosterone insufficiency and may mislead diagnosis toward pseudohypoaldosteronism 6
- Hypoaldosteronism should be considered in the differential diagnosis of hypovolemic hyponatremia with urinary sodium wasting 7
Alternative and Adjunctive Therapies
When Fludrocortisone Causes Problems
- If sodium retention and hypertension develop with fludrocortisone, consider loop diuretics, potassium-exchanging preparations, or bicarbonate as alternatives or additives 4
- In pseudohypoaldosteronism with partial resistance, high-dose fludrocortisone or carbenoxolone (an 11β-hydroxysteroid dehydrogenase inhibitor) may overcome the resistance 8